Searching for images is a common task performed by many computer users. For example, users may search the vast amount of information available via the Internet to find images of particular places or things. While search queries have typically been based solely on keywords, recent technological advances have made other options possible.
Drawing sketches is one of the most natural ways for human beings to communicate with each other, record their thoughts, and express themselves. Touch screen devices, which have become increasingly available and popular, enable users to easily input hand-drawn sketches. Technological advances have also made is possible for users to submit a sketch to be used as the basis for a search for images that are similar to the sketch.
Some sketch-to-image matching techniques primarily consider either shape similarities or color similarities. However, both shape and color convey important information in an image. Accordingly, performing a sketch-to-image match based primarily on shape information may return inferior results due to a lack of consideration of color information. Similarly, a sketch-to-image match based primarily on color information may return inferior results due to a lack of shape information.